I posted on another thread:
The other night at the range my T40 started banging up the mouths of ejected cases. The cases were scrap as far as reloading goes, so I intend to try a new recoil spring. The manual says "D" shaped cases coming out of Kahrs is "normal", but the fact is that the gun never did this before. Kahr CS pointed me to that statement in the manual, so no fix was suggested to me. Continuing would be unacceptable, since I reload and rely on salvaging my brass. Without a fix, the gun will be set aside, possibly sold.
The gun is at about 1000-1500 rounds. I wasn't counting but know I haven't bought, made, or shot great quantities of 40 SW, since it is not a match gun for me. I have two other Kahr 40, neither of which marks the brass to this extent.
Update:
Gunsmith at the range advised that the brass is slamming on the side of the slide on its way out and that is determined by the ejector. Since the gun was not doing this before, he conceded that trying a new recoil spring was worth trying and that the gun may be due for that anyway. He suggested I order another ejector, because it would have to be modified to give the desired angle of ejection and having a backup would be wise.